Sillcock Stem packing - how to replace? FU SAN frost-proof sillcocks

Hi all, we've got a couple of FU SAN anti-siphon frost-proof sillcocks on our house.
(they are made in Taiwan, and appear to be virtually identical to a "Legend T-552")

They're probably ten years old, and one has started to leak out the stem any time it is turned on.
What little info I can find on the web indicates that it is likely time to replace the "stem packing".

I have already tried tightening the nut ("stem gland screw") , but that doesn't slow the leak whatsoever.

I have never opened one of these up, and have no idea what the "stem packing" looks like.
But I'd prefer to have the replacement on hand before I start working on it (have to shut off the water to the whole house first!)

Does anyone know if this 'packing' is a specially formed rubber piece - or can I just use some generic "stem packing" string??

If string isn't going to work, any hints on where I can find a replacement 'packing'???

The factory PDF drawings call it variously NB55, "Rubber", "Buna-n", NBR, and 'same as NBR' - it is part 5-1 in the picture...

If it were mine I would turn the water off to it and take it apart to remove that rubber looking packing. I would then get out my trusty DOW CORNING 111 silicone grease tube and apply a good liberal coat to all of it including the stem and put it back together and see if it leaks. If that does not work I would replace the whole faucet.

What I meant was put a good coat of grease on part 5-1 and put it all back together. Not permanently remove that part and replace it with grease. I misspoke. A little lubrication of O-rings and such can go a long way.

The USA distributor of these things was kind enough to send me a rebuild kit. The sillcock only leaks when OPEN, so I assume its just a stem packing issue, and that the inner seal is OK (though it looks a little ratty).
The stem packing doesn't look nearly as bad as I expected, but its been replaced with the new one now.

I would love to change out the whole inner seal part too, but I cant figure out how to get the old one off!
Do they just pull off, or is there some special removal tool? I don't want to force it and wreck something in the stem there...

edit: figured it out... used needle-nose vicegrips to compress the fitting, then it popped out.
So, the full rebuild has been accomplished.

Thing is, the sillcock still leaks when it's opened ... I guess there is more to the problem than just the stem packing.
I tried tightening the nut gradually, but by the time it was cranked down enough to make the faucet hard to turn, it was still spewing out the water.
(water came out the hole in the stem where the knob screws in, and blocking the hole just made it leak out the bottom of the stem)

I'm a bit puzzled as to the cause... the spring on the end was working smooth, and everything looked exactly right!
The seat inside looks perfectly smooth and clean. (peeked in with flashlight)

The USA distributor of these things was kind enough to send me a rebuild kit. The sillcock only leaks when OPEN, so I assume its just a stem packing issue, and that the inner seal is OK (though it looks a little ratty).
The stem packing doesn't look nearly as bad as I expected, but its been replaced with the new one now.

I would love to change out the whole inner seal part too, but I cant figure out how to get the old one off!
Do they just pull off, or is there some special removal tool? I don't want to force it and wreck something in the stem there...

edit: figured it out... used needle-nose vicegrips to compress the fitting, then it popped out.
So, the full rebuild has been accomplished.

Click to expand...

Hi rockandroller,

I have been looking for the distributor of Fu San sillcock and I just can't find it - I really need to replace a broken part. Can you please let me know their contact?